Stable vertical mechanism



p il 18, 1950 J. D. TEAR 2,504,604

swam: VERTICAL MECHANISM Filed July 1, 1944 2 Sheets-Sheet 1 INVENTORJAMES D. TEAR ATTORNEY J. D. TEAR STABLE VERTICAL MECHANISM April 18,1950 2 Sheets-Sheet 2 Filed July 1, 1944 INVENTOR JAMES D..T EAR Z;

ATTORNEY Patented Apr. 18, 1950 UNITED STATES PATENT OFFICE STABLEVERTICAL MECHANISM James D. Tear, Great Neck, N. Y., assignor to TheSperry Corporation, a corporation of Delaware 3 Claims.

This invention relates to a stabilized level and cross level mechanismfor ships and more particularly to such mechanism under the control of acompensated level gyroscope having its mounting axes fixed with respectto the fore-andaft axis of the ship.

An object of the invention is to provide a novel and improved mechanismof the type above in dicated.

Another object is to provide an improved com= pensating mechanism in adevice of the above type.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

In one embodiment of the present invention as applied to a stablevertical having a gyro with erecting pendulums mechanically connected tomaintain the gyro spin axis vertical, I compensate for the disturbingefiect on the pendulums of acceleration, both due to change of speed anddue to turning of the ship, by a motor driven inertia wheel mounted onthe gyro housing with its axis fixed relative to the fore-and-aft axisof the ship and driven at a speed proportional to the forward speed ofthe ship. In this construction the reaction torque of the inertia wheelto changes in speed produces a force which opposes and compensates forthe force due to the effect upon the pendulums of forward acceleration,and the gyroscopic efiect of the inertia wheel during changes in courseproduces a precession torque which opposes and compensate for the forcedue to the efiect upon the pendulums of transverse accelerationcorresponding to change in course. In this way a single inertia wheel isutilized for complete compensation of the forces due to accelerationacting on the pendulu'ms.

This invention is an improvement on that disclosed in a co-pendingapplication of Poitras and Tear for Vertical-seeking gyro, filed Sept.27, 1937, Ser. No. 165,934, now Patent No. 2,427,158.

Although the novel features which are believed to be characteristic ofthis invention are pointed out more particularly in the claims appendedhereto, the invention itself may be better understood by referring tothe following description, taken in connection with the accompanyingdrawings, in which a specific embodiment thereof has been set forth forpurposes of illustration.

In the drawings: Fig. 1 is a diagrammatic view of a stabilized level andcross-level mechanism embodying the present invention;

P18. 2 is a diagrammatic view of the mechanism for driving the inertiawheel at a speed proportional to the forward speed of the ship;

Fig. 3 is a detail view of the control mechanism for the level and crosslevel motors; and

Fig. 4 is a partial section through one pair of control contacts.

Referring to the drawings more in detail, particularly to Fig. l, apedestal I0 is shown as mounted on a base H which is attached to theship in a fixed position and carries a fixed bracket l2, which, in theembodiment shown, is assumed to be positioned in the fore and aft planeof the ship and carries a roll gimbal M which is pivoted to the bracketl2 for relative movement in roll, but is fixed to move with the bracketi2 in pitch.

A sleeve 18 is journalled for rotational movement about the pedestal H).The sleeve l8 carries a train bracket l9 which is mounted to be movablein train and has attached thereto a gear 28 driven by a pinion 2|mounted on a shaft 22 which is driven through bevelled gears 23 from atrain input sraft 2d. The train input shaft 24 is actuated by anysuitable means to follow the bearing of a target and produces acorresponding movement of the train bracket [9.

The train bracket l9 carries a cross level ring 28 which is mounted onpivot pins 29 and 30 for movement in cross level with respect to thetrain bracket l9, but is constrained to move with the train bracket l9in level. A stable ring 3| is pivoted to the cross level ring 28 bysuitable means shown as pivot pins 32. The stable ring 3| is caused toremain horizontal by the means to be described.

The cross level ring 28 is power driven by a reversible motor mounted onthe train bracket is and driving a shaft 36 through bevelled gears 31.The shaft 35 carries a pinion 38 meshing with a segmental rack 39attached to the cross level ring 28. The movement of the cross levelring is transmitted to a distant point for control purposes by means ofa transmitter 40 which is mounted on the train bracket l9 and is drivenby a bevelled gear 4| to reproduce the movement of the shaft 36.

The stable ring 3| is power driven by means of a motor attached to abail 46 carried by the stable ring 3| and driving a shaft 41 throughbevelled gears 48. The shaft 41 carries a pinion 49 meshing with asegmental rack 50 formed on' a bracket 5| attached to the cross levelring 28. The movement of the stable ring with respect to the cross levelring 28 is transmitted to a distaut point for control purposes by atransmitter 52 which is mounted on the bail M5 and is driven by abevelled gear 56 from the gear 46 on the shaft 41.

The motors 65 and 45 are controlled by a gyroscope 66 which is mountedby pivot pins 6| on a sensitive gimbal 62. The sensitive gimbal 62 ispivoted by pins 63 to a phantom gimbal 64 and to the roll gimbal I4 sothat the gyroscope 66 is free to move in all directions with respect tothe fixed bracket I2. The phantom gimbal 64 carries a ball 66 which isjournalled for rotational movement in a sleeve 61 attached to the ball46 so that the bails 46 and 66 move in unison except that the bail 46may be rotated in train about the axis of the sleeve 61, whereas theball 66 is fixed in train by means of the fixed bracket I2 and rollgimbal I4.

The axis of the sleeve 61 is aligned with the center of the gimbalsystem.

A rod 16 attached to the casing of the gyroscope 66 and fixed tocoincide with the spin axis of the gyroscope, extends upwardly throughthe sleeve 61 and loosely carries at its upper end a pair of brackets Hand 12 as shown in Fig. 3 to which are pivoted arms 16 and 14respectively carrying contact rollers and 16 respectively. The contactrollers 15 and 16 ride in channels 11 and 16 attached to brackets 16 and66 carried by the bail 46. The channel 11 extends in the plane of thebail 46 whereas the channel 16 extends at right angles thereto. Theroller 15 selectively makes contact with a pair of contact members 6Iand 62 positioned in the channel 11 and the roller 16 selectively makescontact with a pair of contact members 63 and 64 positioned in thechannel 16. The rollers 15 and 16 riding in the channels 11 and 16 causethe brackets H and 12 to turn with the bail 46 about the rod 16.

The contact members 6| and 62 are connected by conductors 9| and 62 tothe cross level motor 65 above described. The contact members 66 and 64are connected by conductors 66 and 64 to the level motor 45 abovedescribed. The return leads from the motors 65 and 46 are connected byconductor 65 to one side of a power supply line 96. The contact arms 16and 14, carrying the rollers 15 and 16, are connected by a conductor 61to the other side of the power supply line 66. The connections are suchthat *the motors 35 and 45 are reversibly driven in a direction whichtends to maintain the rollers 15 and 16 on the insulating segmentsbetween their respective contacts.

sired, that the action of the pendulums I66 and NI and the gyroscope 66are disturbed by the effect of accelerations either in a fore and aftdirection due to change in speed of the ship or in a transversedirection due to the turning of the ship. In accordance with the presentinvention, I have found that this disturbing effect may be compensatedfor by means of an inertia wheel I 26 which is mounted on a shaft HI andis driven by a motor I22 which is mounted on the housing or casing ofthe gyroscope 66 with the axis of the shaft I2I extending in afore-and-aft direction. The motor I22 is driven at a speed proportionalto the speed of the ship by means to be described, so that when thespeed changes a reaction torque is developed which applies a torque tothe casing of the gyroscope 66 in a direction to oppose the torqueproduced by the effect of The rollers 16 and 16 on the arms 16 and 14are held in contact with the contact members by means of springs 66which extend between said arms and the ball 46. Sufllcient clearance isprovided in the sleeve 61 around the rod 16 to permit the relativemovement required for control purposes.

The phantom gimbal 64 carries a pair of erecting pendulums I66 and INwhich carry arms I62 and I63 respectively and are pivoted onpivot pinsI64 and I65 projecting from the phantom gimbal 64. The arm I62 isprovided with a forked end I66 which engages a pin I61 attached to thehousing of the gyroscope 66. The arm I63 is provided with a forked endI66 which engages a I pin I66 attached to the sensitive gimbal 62.

Counterweights I I6 and I II are provided for balancing the arms I62 andI66 and for adjusting the zero position of the pendulums I66 and IN.

The action of the erecting pendulums I66 and I" is well known in the artand is such as to apply precessing forces to the gyroscope 66 suited tomaintain the spin axis of the gyroscope subsaid change in speed on thependulum I66 as explained more in detail in the copending application ofPoitras and Tear above identified.

The effect on the pendulum I6I of any turning motion of the ship isopposed by the gyroscopic effect of the inertia wheel I26 which producesa torque on the casing of the gyroscope 66 in a direction to oppose thetorque produced by the effect of such turning movement on the pendulumIN. This operation may be explained as follows:

Assume the arrow I26 to indicate the direction of the bow of the shipand the inertia wheel I26 to be rotating in a counter-clockwisedirection as viewed when looking toward the bow as in Fig. 1; the effectof positive acceleration, that is. an increase in speed of the ship,would tend to cause the pendulum I66 to swing backwardly and cause adownward movement of the arm I62 which tends to turn the gyroscope 66 ina counter-clockwise direction about the pivot pin 6I. As will beexplained, an increase in speed of the ship also produces acorresponding acceleration or increase in speed of the driving motor I22which produces a reaction torque in a clockwise direction on the housingof the gyroscope 66 which opposes the torque due to the pendulum I66. Bysuitable design of the motor I22 and inertia wheel I26 with respect tothe pendulum I66, these torques may be made equal and opposite so thatthe effect of forward acceleration on the pendulum and therefore on thegyroscope 66 is eliminated.

If the ship should turn to the right, for example, this movement tendsto cause the pendulum I6I to swing to the left, thereby raising the armI63 and applying an upward force to the pin I66 which is attached to therear of the sensitive gimbal 62. However, when the shaft I2I is turnedto the right by the movement of the ship, a precession torque isproduced due to the gyroscopic effect of the reaction wheel I26 which"tends to turn the rear of the sensitive gimbal 62 in a downwarddirection. When the design of the inertia wheel and motor I22 is correctto neutralize the effect of acceleration on the pendulum I66 theprecession torque due to the inertia wheel 5 will be equaland oppositeto the torque produced by the inertia of the pendulum Il so that theeflect of transverse acceleration is likewise equalized. Hence, the spinaxis of the gyroscope remains vertical and is unafiected by accelerationin any direction.

It will be noted that the rotational movement of the train bracket I9due to changes in bearing of the target is not transmitted to thegyroscope which is fixed in a fore-and-aft position by the fixed bracketI2. Hence no disturbing force is introduced to the gyroscope and itsassociated mechanism by this movement of the train bracket and the rodI0 thus stays vertical at all times.

Any relative movement between the rod I and the ball 46 in the plane ofthe contact arms I3 and I4 causes the rollers I5 and I5 to energize thecorresponding contact member and thereby actuate the cross lever motor35 or the level motor 45 so as to drive the cross level ring and thestable ring 3I in a direction to bring the insulation between therespective contact members under the rollers I5 and I5. The stable ring3I is thus caused to follow the movement of the gyroscope 50 and toremain in a horizontai position. The phantom gimbal 5% which moves withthe stable ring 3i, due to the connection through the sleeve 51,maintains a horizontal position under the control of the gyroscope 50.

The mechanism for driving the motor I22 at a speed proportional to thespeed of the ship is shown in Fig. 2. Referring to this figure, a dynamic pressure tube I is shown as extending through the hull I3I intothe surrounding water and is provided with a forwardly directed orificeI32. A static pressure tube I33 likewise extends through the hull I3!and is provided with a lateral orifice I34. The dynamic pressure tubeI35 and the static pressure tube I33 connect with chambers formed in acasing I on opposite sides of a flexibly mounted diaphragm MI and arearranged to apply unbalanced pressure forces on the diaphragm I4I whichare dependent upon the speed of the ship.

Movement of the diaphragm I4I due to the unbalanced forces istransmitted by a link I42 to an arm I43 which is pivoted at one end by afixed pin I44. The arm I43 actuates a second arm I45 which is pivoted bya fixed pin I41 and carries a slide I48 which is adjustable along thearm I45 by means of a threaded screw I45 and is provided with a surfaceengaging the arm I43. Consequently, the ratio of movement of the arms I43 and I45 may be controlled by adjusting the slide I48 and therebyvarying the point of contact of the slide with the arm I43.

The arm I45 carries a lug I50 to which an insulated contact I5I isattached. This contact I 5I cooperates with a stationary contact I52 toclose a circuit from a power source I53 to a motor The motor I 54 drivesa shaft I58 carrying a support I59 to which inertia weights I50 arepivotally mounted to swing outwardly by centrifugal force as the shaftI58 rotates.

The inertia weights I50 are provided with shoulders I5I which engage acollar I52 attached to link I53 which is pivoted at I54 to the arm I45and is arranged so that the force produced by the centrifugal forceacting upon the weights I causes the link I53 to move the arm I45 in adirection to open the contacts I 5| and I52 and to oppose the unbalancedforce exerted by the pressures acting on the diaphragm MI.

The pressure on the diaphragm I from the tube I30 tends to move thediaphragm I in a direction to close the contacts I5I, I52 and therebycause the motor I54 to operate. Operation of the motor I54 causes theinertia weights I50 to swing outwardly and thereby exert a force on thelink I53 and arm I45 which opposes the force exerted by the diaphragm I.When the force exerted by the inertia weights I50 equals the forceexerted by the diaphragm Hi, the contacts are again opened and the motorbegins to slow down. As the motor slows down, the force exerted by theinertia weights E55 is reduced, thereby allowing the contacts to againclose and cause the motor to speed up. In this way, by rapidly openingand closing the contacts, the motor I54 is caused to operate at a speedwhich is controlled by unbalanced pressures on the diaphragm I4I due tothe forward movement of the vessel. It is to be noted that the pressuredevice, including the diaphragm Mi, operates on the square lawprinciple. The inertia weights I50 likewise operate on the square lawprinciple. Hence the square law effects cancel out and the motor I54 iscaused to operate at a speed which is directly proportional to theforward speed of the ship.

The motor I54 carries a pinion I55 which drives a gear I59 through anidler I10. The gear I59 is mounted on the shaft III of a syn-= chronoustransmitter I12 which is connected to drive the motor I22 of Fig. 1. Thesynchronous transmitter I12 and the motor I22 are designed so that themotor I22 operates at a speed which is dependent upon the speed of thesynchronous transmitter IIZ. Consequently, the motor I22 at all timesmaintains a speed proportional to the forward speed of the ship.

While the bracket I2 has been described as fixed parallel to thefore-and-aft axis of the ship, it is to be understood that this bracketmay take other positions, in which event, the pendulums I00 and NI willbe acted upon by their respective components of the forward accelerationand transverse acceleration. While two pendulums are shown, an erectingsystem using one universally mounted pendulum may be used. The axis ofthe shaft I2I must, however, be fixed relative to the pendulum orpendulums so that the reaction torques due to the inertia wheel I20during change of speed of the ship will oppose and neutralize the torqueresulting from the acceleration force acting on the pendulum orpend-ulums due to the change of speed of the ship and the gyroscopicprecession torque resulting from the inertia wheel I20 will oppose andneutralize the torque resulting from the centrifugal force acting on thependulum or pendulums due to change of course of the ship.

It is to be understood that the inertia wheel and driving means may bemounted on or directly it stable memberhaving an erecting pendulum to 7maintain said member in a stable position, means supporting the stablemember on .the ship for pivotal movement about axes having a fixedangular relation in train to the iore-and-att axis 01' the ship, aninertia. wheel and a synchronous driving motor therefor mounted on saidstable member with their axes of rotation fixed in train with respect tothe axes of the supporting means, a pressure actuated member responsiveto the forward movement of the ship, a motor control member connected tobe actuated in response to the force exerted by said pressure actuatedmemher, a motor connected to be energized by said motor control member,means driven by said motor for generating a force representative of thespeed of said motor, means applying said generated force to oppose theforce exerted by said pressure actuated member, a synchronoustransmitter driven by said motor, and means connecting the synchronousmotor to be driven by said synchronous transmitter.

2;. In a pendulous mechanism for use on a moving platform, a pendulouselement, means supporting the pendulous element on the platform forpivotal movement about axes having fixed predetermined angular relationin train to the axis oi movement of the platform, an inertia wheelmounted on the pendulous element with its spin axis of rotation fixed intrain in relation to the axes of the supporting means, and meansreacting on the pendulous element for driving the inertia wheel aboutits spin axis at a speed proportional to the speed of the platform,whereby the torques due to changes of speed of the inertia wheel opposethe disturbing torques acting on the pendulous element due to thecorresponding changes of speed of the platform and the torques due tothe gyroscopic effect of the inertia wheel 'due to changes in directionof movement of the platform oppose the disturbing 40 torques acting onthe pendulous element due to said changes in direction of movement orthe platform.

3. mastabiliaedtoruseonacrait including a pendulum, means supporting thestabilized mechanism on the craft for pivotal movement about. axeshaving ilxed predetermined angular relation in train to the tore-andaftaxis of the craft, and means compensating for the effect 01 accelerationon said pendulum comprising an inertia wheel and driving means thereformounted with their spin axes in fixed angular relation in train to theaxes of the supporting means, meansrotating said inertia wheel anddriving means about their spin axes at a speed proportional to the speedof the craft, and means operably connecting said inertia wheel anddriving means to the pendulum to apply the reaction torque of thedriving means to oppose the eflect of acceleration oi the craft on saidpendulum and to apply the torque due to the gyroscopic effect of theinertia wheel during turning of the craft to oppose the effect on saidpendulum oi transverse acceleration due to said turning.

JAMES D. TEAR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,579,038 Smoot Mar. 20, 19261,679,354 Fairchild et al Aug. 7, 1928 1,731,776 Henry Oct. 15, 19291,840,104 Anschutz-Kaempie Jan. 5, 1932 1,932,210 Giitscher Oct. 24,1933 2,297,274 Wunsch Sept. 29, 1942 2,332,611 Spencer Oct. 26, 19432,382,993 Haskins Jr. Aug. 21, 1945 FOREIGN PATENTS Number Country Date530,764 Germany Aug. 1, 1931

